Technical Field
The present invention relates to a terminal device for transmitting results obtained by measuring (metering) physical quantities by plural measurement sensors, a communication system including the terminal device, and a method of activating the terminal device.
Background Art
In a sensor network system, a sensor terminal device performs transmission of results obtained by measuring physical quantities by measurement sensors to a base station device.
In a wireless sensor described in PTL 1, power of a power supply unit can be supplied when a sensor to be operated without the power is in an on-state, power of the power supply unit is not supplied when the sensor is in an off-state, and a transmission unit performs transmission of given information by wireless communication to the outside by receiving the power of the power supply unit.
In a sensor network system managing method described in PTL 2, a residual driving time of a battery in each sensor is acquired, a target residual driving time is set and an operation of each sensor is controlled so as to roughly equalize the residual driving time of the battery in each sensor with the target residual driving time in a sensor network system managing device capable of performing communication with plural sensors and receiving sensor information from respective sensors as well as performing operation control with respect to respective sensors. More specifically, the target residual driving time is set to a residual driving time of a battery in a sensor having the longest residual driving time of the battery at that time, and the remaining capacity of the battery is detected as well as a target average power consumption is calculated by the remaining capacity and the target residual driving time, thereby controlling the operation of the sensor so as to realize the target average power consumption.